The hours file has been nixed. Moria can be played at all times on any day.

Increased the maximum number of classes from 8 to 32.

Increased the maximum number of spells from 32 to 2^32-2. This changes the save-game format.

Increased the maximum number of scroll, wand and staff effects to from 32 per TVAL to 2^32-1. TV_SCROLL2 has disappeared. The opportunity for multiple simultaneous effects has disappeared for these TVALs (but none had multiple simultaneous effects anyway, like potions and food have).

Added new "resist poison gas" spell and prayer for Mages and Priests. It confers a permanent & small resistance to poison gas on the character. This is meant to offset the threat of a gas attack by an Ancient Multi-Hued dragon by enough to make it a little more fair (e.g. not as many insta-deaths). The resistance is damage / 1.5.

added gender-based class titles.

once traps go off, they're gone.

displaying hit-points and mana points in a more familiar-looking x/y format.

If you're playing the game and trying to understand how to play, the Game Manual will definitely help. If you're trying to use the compilers that build monsters, items, races and classes into the game, check out the documentation section.